Chemiluminescent aerosols



3,502,588 CHEMILUMINESCENT AEROSOLS Hilmer E. Winberg, Wilmington, DeL,assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., acorporation of Delaware No Drawing. Filed May 18, 1966, Ser. No. 550,927Int. Cl. C091; 3/30, 1/02 US. Cl. 252-188.3 Claims ABSTRACT OF THEDISCLOSURE Described and claimed are chemiluminescent aerosolscontaining tetrakis(disubstitutedamino)ethylenes in suitablepropellants, e.g., tetrakis(dimethylamino)ethylene in a fiuorinatedhydrocarbon.

Related applications FIELD OF THE INVENTION This invention relates to,and has as its principal object provision of, chemiluminescent aerosolsbased on tetrakis(disubstitutedamino)ethylenes, i.e.,pertertiaryaminoethylenes.

DESCRIPTION OF THE INVENTION Pruett et al., J. Am. Chem. Soc. 72, 3646(1950) prepared the first member of the series of thetetrakis(disubstitutedarnino) ethylenes, i.e., tetrakis dimethylamiuo)ethylene (TMAE). US. Patent 3,239,519 describes and claims other relatedcompounds to complete the series of compounds in which the Rs, which canbe alike or different, are straight or branched chain alkyl or cyloalkylhydrocarbon radicals of from 1-10 carbons each, preferably of no morethan five carbons each, which can be joined pairwise on one nitrogen toform 3-5 membered monoaza heterocycles and on two nitrogens to form 4-7membered diaza heterocycles. See also US. Patent 3,239,534 for apreparation of all of these compounds.

In accordance with the present invention, it has been found that usefulchemiluminescent areosols can be readily made from the above-identifiedseries of compounds by combining them in finely divided form withappropriate propellants. The areosol or aerosol-generating mixtures perse consist essentially of at least one nonquenching propellant, e.g.,1098% by weight, and an efiective chemiluminescing amount, e.g., 902%,of at least one of the compounds named above, but inert materials whichdo not interfere with the function of the propellant or quench theluminescent material can also be present.

The term aerosols is believed to be well known to the packaging art. Thefirst and probably most scientific usage thereof occurred in earlycolloidal chemistrysee, for instance, Whitlaw-G-ray and Patterson,Smoke, Arnold and Company, Limited, London (1932), as de- 3,502,588Patented Mar. 24, 1970 fining a colloidal system consisting of veryfinely subdivided liquid or solid particles dispersed in and surroundedby a gas. More recently, Sinclair in Handbook on Aerosols (1950),Washington, D.C., on page 64, stated that such particles should besmaller in diameter than 50 microns and usually less than 10 microns. Inthe early 1940s, this term was used to describe insecticides packed in aself-pressurized pack and the Chemical Specialties ManufacturersAssociation, Incorporated, of New York evolved the following definitionof an aerosol product:

A self-contained sprayable product in which the propellant force issupplied by a liquefied gas. Includes space, residual, surface coating,foam and various other types of product but does not includegas-pressurized products such as whipping cream. The term aerosol asused here is not confined to the scientific definition.

The best modern definition is believed to be as follows:

A much more satisfactory term for the subject described in this book ispressurized pack which may be defined as a self-contained pack whichcontains the product and the propellant necessary for the expulsion ofthe former. This definition includes packs which utilize compressedgases as propellants and, by discarding the term aerosol,acknowledgement is made of the fact that this word has a scientificmeaning.

These foregoing two quotations are taken from Pres surized Packaging(Aerosols) by Herzka and Pickthall, Academic Press, New York (1958).

Recognizing that some confusion does exist and that the last quoteddefinition is the most recent, the term aerosols is used here ascovering generically all pressurized packs including those where thepropellant is a pressurized gas, either supplied in situ from anotherstate form thereof, or where the pressurized gas is charged as suchdirectly. In any event, however, and regardless of the specificdefinition used, aerosols are regarded in this application primarily ascomposition-of-matter, i.e., mixtures, containing the propellant and aneffective chemiluminescent amount, i.e., down to about 2% by weight, ofthe chemiluminescent material and any inert substance desired. Both thepropellant and any inert substance should, of course, be nonquenching tothe chemiluminescence: cf. my US. Patent 3,264,221.

The possible variables in the formulation of these chemiluminescentaerosols as to propellants, dispenser components, filling techniques,laboratory evaluation, formulations, and the like, are the same as thoseknown already in the general aerosol art, all as discussed in detail inthe above definitive text by Herzka and Pickthall. The only variation inthe present compositions and techniques over those discussed in thispublication is the necessary presence of one or more of thechemiluminescent tetrakis (disubstitutedamino)ethylenes which serve torender the thus formulated aerosols chemiluminescent. By reference tothis publication all disclosures and discussions therein are made commonto this specification.

In the foregoing and elsewhere, reference is made to chemiluminescentaerosols. It is recognized that this is not always correct since some ofthe compositions in aerosol form do not chemiluminesce per se. However,in all instances when the aerosol containing the chemiluminescenttetrakis(disubstitutedamino)ethylene is deposited on a necessarilyultimate surface, and contact is established with oxygen, air, aperoxide, etc., chemiluminescence will occur. In most cases,chemiluminescence appears upon mere contact of the chemiluminescentmaterial with the oxidizing agent. Compare, with respect to oxidizingagents, my above-mentioned US. Patent 3,264,221.

The propellent gases used in the present invention are conventionalaerosol propellants but must contain no oxidizing oxygen, be essentiallyinsoluble in the composition to be propelled from the container, and beinert, or nonquenching, toward the above chemiluminescentpertertiaryaminoethylenes. Representative operable propellent gases arechlorodifluoromethane (Du Pont Freon22), dichlorofluoromethane(Freon21), dichlorodifluoromethane (Freon-12), 1,2dichlorotetrafiuoromethane (Freon-114), octafiuorocyclobutane (FreonC318), chloropentafiuoroethane (Freon 115) and mixtures such as F-l2 andtrichlorofluoromethane (Freon 11), F-lZ and F22, F-l2 and I -114, F22and F-ll, and F22 and F-l 14 (cf. Wahlin U.S. Patent 3,062,751). Inertcompressed gases like nitrogen and helium may be used but they are lessadvantageous than the above-mentioned fluorine-containing compounds andtheir mixtures.

It may be stated that aerosols in which the chemiluminescent componentis tetrakis(dimethylamino)ethylene are essentially nonoxyluminescent invapor form when the propellant(s) is one of the polyfiuorocarbon typesbut are oxyluminescent when using other propellants such as nitrogen(seen Example 12). Aerosols in which the oxyluminescentpertertiaryaminoethylene component is of the tetraall yl-A-bi(imidazolidine) structure, even with the polyfiuorcarbon propellants,give oxyluminescent clouds which continue their oxyluminescence whendeposited on a surface (see, for instance, Examples l3, 14,

15,16, l8, 19, 22, 24, 25, and 26).

Other useful low-boiling materials can be used as the propellant in theaerosols of the present invention. As is true of all such, the primarycriteria involved in adjudging whether or not a material is useful as apropellant hinge primarily on its boiling point and vapor pressure, andpartial pressure in the charged systems in the aerosol containersphysically speaking. Chemically speaking, the only overriding criterionis that the material for the propellant must be unreactive with thechemiluminescent peraminoethylene serving as the active ingredient inthe overall aerosol formulation. Accordingly, in addition to theforegoing described polyfluorohydrocarbons, other compounds can be usedas propellants such as, for instance, the low-boiling hydrocarbonethers, e.g., dimethyl ether, and to a lesser extent, methyl ethylether; the lowboiling saturated aliphatic hydrocarbons such as, forinstance, propane, isobutane, butane, and the like.

If desired, and as possibly necessary for viscosity control, inertsolvents or diluents can also be present in the aerosol charge. Suchdiluents must, of course, be unreactive chemically with mostimportantly, the chemiluminescent pertertiaryaminoethylene and also withthe propellant(s). Suitable specific examples of such possibly usefuldiluents are the liquid hydrocarbons such as cyclohexane, methyl andethyl cyclohexanes, and the like, the higher aliphatic hydrocarbons suchas decane, Nujol purified kerosene, mineral oils, and the like, as wellas the lower-boiling hydrocarbons such as, for instance, cyclopentane,cyclobutane, and for that matter, cyclopropane, and the like. Alsouseful are the higher boiling species of the previously describedpropellants such as, for instance, the hydrocarbon ethers, e.g.,diethyl, dipropyl, dibutyl ether, and the like. Silica or other inertpowders can also be present to give powder aerosols.

The following examples in which the parts given are by weight aresubmitted to further illustrate the present invention but not to limitit. All tetrakis(disubstitutedamino)ethylenes disclosed except TMAEitself are within the scope of my US. Patent 3,239,519.

EXAMPLES l-9 Aerosols containing tetrakis(dimethylamino)ethylene (TMAE)were prepared by charging TMAE into standard aerosol containers undernitrogen. Aerosol valves were then attached to the containers and thepropellants were .Nujol is medicinal grade liquid petrolatum.

injected into the containers through the valves. The following tablelists the compositions in parts by weight.

Dichlorodi- Dichlorodi- Dichlorodifluorofluorofluoromethane/ methane]methane/ trichlorotrichlorotriehlorotluorofluorofluoro- Dichloromethane,methane, methane, difluoro- TMAE 20/80 30/70 50/50 methane EXAMPLE 10 Anaerosol was prepared comprising 15 parts of TMAE, 32 parts ofperfiuorocyclobutane, and 18 parts of dichlorodifluoromethane. Theaerosol gave a cloud which chemiluminesced on settling on a surfacecontacting the air.

EXAMPLE 11 An aerosol was prepared comprising 15 parts of TMAE and 20parts of isobutane. The aerosol gave a cloud which chemiluminesced for aconsiderable time after settling on a surface in contact with air.

EXAMPLE 12 TMAE was sprayed from a paint sprayer under nitrogen pressureto give a cloud which chemiluminesced on settling on a surface. When theTMAE was shaken with air to obtain a strong luminescence in the liquidbefore spraying, the cloud was then luminous.

EXAMPLE 13 By the procedure of Example 1, an aerosol was prepared whichcomprised 10 parts of 1,1',3,3'-tetraethyl- A '-bi(imidazolidine) and 22parts of isobutane. When sprayed in air in the dark, the aerosol formeda luminous cloud which was bright and of good duration.

EXAMPLE 14 By the procedure of Example 1, an aerosol was prepared whichcomprised five parts of 1,1',3,3-tetraethyl- A -bi(imidazolidine), fiveparts of diethyl ether, and 22 parts of isobutane. When sprayed in airin the dark, the aerosol formed a luminous cloud of good brightness andduration.

EXAMPLE 15 By the procedure of Example 1, an aerosol was prepared whichcomprised 4.3 parts of 1,1,3,3'-tetramethyl- A '-bi(imidaZ0lidine), fiveparts of cyclohexane, and 22 parts of isobutane. V/hen sprayed in air inthe dark, the aerosol formed a luminous cloud of good brightness andduration.

EXAMPLE 16 By the procedure of Example 1, an aerosol was prepared whichcomprised 10 parts of diethyldimethyl-A bi(imidazolidine) and 22 partsof isobutane. When sprayed in air in the dark, the aerosol formed aluminous cloud of good brightness and duration.

EXAMPLE 17 Example 13 was repeated but employing 20 parts of1,1',3,3-tetraethyl-A '-bi(imidazolidine) and 17 parts of isobutane.When sprayed in air in the dark, the aerosol formed a luminous cloudwhich was bright and of good duration.

EXAMPLE 18 By the procedure of Example 1, an aerosol was prepared whichcomprised 13 parts of 1,l',3,3-tetraethyl- A '-bi(imida'zolidine) and 44parts of 1,2-dichlorotetrafluoroethane. When sprayed in air in the dark,the aerosol formed a luminous cloud which was bright and of goodduration.

EXAMPLE 19 By the procedure of Example 1, an aerosol was prepared whichcomprised parts of 1,l',3,3-tetraethyl- A '-bi(imidazolidine) and 40parts of dichlorodifiuoromethane. When sprayed in air in the dark, theaerosol formed a luminous cloud which was bright and of good duration.

EXAMPLE 20 By the general procedure of Example 1, the following sprays,powder aerosols and short grease aerosols were prepared using theindicated ingredients in the proportions given. In all cases theresultant aerosol-type products resulted in significant and notablylong-range existing chemiluminescence when sprayed in air, particularlywhen con- Silica pigment (commercially available pyrogenic particulatesilica of 0020-0007 micron particle size range; 99.0-99.7% SiO TMAEDichlorodifluoromethane 1,Z-dichlorotetrafiuoroethane (/60 by weight)90.8

Percent Short grease aerosols Silica pigment Decane TMAEDichlorodifiuoromethane Isobutane EXAMPLE 21 By the procedure of Example1, an aerosol was prepared which comprised parts of TMAE and 5 parts ofdichlorodifluoromethane. Objects in contact with air wet with the sprayfrom the aerosol were rendered visible in a darkened room by thechemiluminescence of the TMAE deposited thereon. The chemiluminescencewas bright and of long duration.

EXAMPLE 22 By the procedure of Example 1, an aerosol was prepared whichcompared 37.5 parts of TMAE, 12.5 parts of 1,1',3,3'-tetraethyl-A'-bi(imidazolidine) and parts of dichlorodifluoromethane. When sprayedin air in the dark the aerosol formed a bright luminous cloud. Materialdeposited on a surface luminesced brightly with good duration.

6 EXAMPLE 23 By the procedure of Example 1, an aerosol was prepared from21.5 parts of TMAE, 22.2 parts of Nujol, 0.83 part of decyl alcohol and50 parts of dichlorodifluoromethane. Material deposited from the aerosolon a surface contacting air chemiluminesced brightly and with goodduration.

EXAMPLE 24 Part A.Preparation of 1,1',3,3'-tetra n butyl-Abi(imidazolidine) In a glass reactor fitted with a packed distillationcolumn, condensing means, and a distillation takeoff head, a mixture of23.8 parts of a,a-dimethoxytrimethylamine and 34.5 parts ofN,N-di-n-butylethylenediamine was heated in an oil bath at 114 C. Over afour-hour period the oil bath temperature was gradually increased to 190C. during which time the dimethylamine and methanol formed in thereaction Were removed by distillation. Continued distillation gave 26.5parts (73% of theory) of l,1,3,3-tetra-n-butyl-A -bi(imidazolidine) as aliquid boiling at 128 C. under a pressure corresponding to 0.20 mm. ofmercury. The product luminesced strongly on exposure to air.

Analysis.-Calcd for C H N (percent): C, 72.5; H, 12.2; N, 15.4. Found(percent): C, 72.5; H, 12.4; N, 14.8.

Part BAerosol By the procedure of Example 1, an aerosol was preparedfrom 20 parts of l,1,3,3-tetra-n-butyl-A -bi(imidazolidine), 20 parts ofdecane containing 4% decyl alcohol by Weight and 40 parts of a 30/70mixture of dichlorodifiuoromethane/trichlorofluoromethane by weight.When sprayed in air in the dark, the aerosol formed an orangecoloredluminous cloud.

EXAMPLE 25 Part A.Preparation of 1,1,3,3-tetra-n-hexyl-Abi(imidazolidine) A mixture of 23.8 parts of a,a-dimethoxytrimethylamineand 45.7 parts of di-n-hexylethylenediamine was heated in a reactor asdescribed in Example 24, Part A, with the bath slowly rising over aperiod of 4 hours from 107 to 200 C. and the methanol and dimethylamineformed during the heating being removed by distillation. Continueddistillation gave 37.0 parts (77% of theory) of1,1',3,3'-tetra-n-hexyl-A '-bi(imidazolidine) as a liquid boiling at C.under a pressure corresponding to 0.20 mm. of mercury. The productluminesced strongly on exposure to air.

Analysis.-Calcd for C H N (percent): C, 75.6; H, 12.7; N, 11.8. Found(percent). C, 75.7, 75.8; H, 12.4, 12.8; N, 12.1.

Part B.-Aerosol By the procedure of Example 1, an aerosol was preparedfrom 17.2 parts of 1,l,3,3-tetra-n-hexyl-A '-bi(imidazolidine), 17.2parts of decane containing 4% decyl alcohol by weight and 34.4 parts ofa 30/70 mixture of dichlorodifiuoromethane/trichlorofiuoromethane byweight. When sprayed in air in the dark, the aerosol formed anorange-colored luminous cloud.

EXAMPLE 26 By the procedure of Example 1, an aerosol was prepared from20 parts of tetrakis(N-pyrrolidinyl)ethylene, 20 parts of decanecontaining 4% decyl alcohol by weight and 40 parts of a 30/70 mixture ofdichlorodifiuoromethane/trich1orofluoromethane by weight. The aerosolformed a luminous cloud when sprayed in air in the dark.

EXAMPLE 27 Part A.-l-dimethylamino-1,2,2-tris(N-pyrrolidinyl) ethyleneTo 126 parts of dimethyl sulfate heated at 6570' C.

was added with stirring 73 parts (an equimolar proportion) ofdimethylformamide over a period of about 30 minutes. The reactionsubsequently became exothermic and the reaction temperature wasmaintained at 6570 C., as needed, by external cooling of the reactor.After the exothermic reaction had subsided, the reaction mixture wasmaintained at 6570 C. for an additional minutes. There was then addeddropwise with continued stirring to the reaction mixture at 6065 C. 71parts (an equimolar proportion) of pyrrolidine over a period of 1.5hours. The reaction mixture was maintained at that temperature for anadditional minutes and then stripped by distillation under reducedpressure (30 mm. of mercury) to a bath temperature of 90 C. to removemost of the methanol formed in the reaction. The residue was thendiluted with about 110 parts of benzene and 54 parts (an equimolarproportion) of sodium methoxide was then added with stirring andmoderate external cooling to maintain the reaction temperature below C.The reaction mixture was stirred for five hours, filtered, the solidfilter cake washed with benzene, and the resultant filtrate subjected todistillation. There was thus collected ml. of the benzene/methanolazeotrope equiv alent to 0.4 molar proportion of methanol boiling at 58C. On continued distillation there was obtained 87 parts of a crudeproduct boiling over the range 38-79 C./20.01.6 mm. of mercury. Thisliquid was heated in an oil bath for eight hours while gradually raisingthe bath temperature to 210 C. at atmospheric pressure while collectingall volatile material. There was thus obtained 17 ml. of largelymethanol, and on distillation of the resultant liquid residue there wasobtained 18.3 parts (20% of theory) of l-dimethylamino-l,2,2-tris-(N-pyrrolidinyl)ethylene as a light yellow liquid boiling at 104112 C.(almost all at 109ll2 C.)/O.15 mm. of mercury. Thedimethylaminotris(N-pyrrolidinyl)ethylene was identified by its IR andn-m-r spectra.

Analysis.--Calcd for C H N (percent): C, 69.0; H, 10.9; N, 20.1. Found(percent): C, 69.0; H, 11.2; N, 20.8.

Part B.Aerosol By the procedure of Example 1, an aerosol was preparedfrom 6.1 parts of 1,1,2-tris(N-pyrolidinyl)dimethylaminoethylene, 6.1parts of decane containing 4% decyl alcohol by weight and 12.2 parts ofa 30/70 mixture of dichlorodifiuoromethane/trichlorofiuoromethane byweight. Material deposited from the aerosol on a surface chemiluminescedin air with moderate duration.

EXAMPLE 28 Part A.Preparation of bis(N-pyrrolidinyl) methylene-1,3-dimethyl-Z-imidazolidine CH; N/ e k -N A mixture of 28.5 parts ofpyrrolidine, 17.6 parts (0.5 molar proportion) ofN,N'-dimethylethylenediamine, and 29.2 parts (an equimolar proportion)of dimethylformamide/dimethyl acetal was heated in an oil bath up to abath temperature of 100 C. While collecting all distillate. Over aperiod of four hours there was thus collected 18 ml. of dimethylamine(theory, 26.6 ml.) by condensation in an attached solid carbondioxide-cooled trap. The bath temperature was gradually raised to 190 C.over a period of four hours, during which time there was collected 29ml. (theory, 32.4 ml.) of crude methanol. Distillation of the liquidresidue aflForded 13.4 parts (27% of theory) of crudebis(N-pyrrolidinyl)methylene-1,3-dimethyl-Z-imidazolidine as a liquidboiling over the range 86-138" C./1.350.1 mm. of mercury, largely at136- 138 C., and 15.5 parts (31% of theory) of pure bis(N- 8pyrrolidinyl)methylene-l,3-dimethyl-Z-imidazolidine boiling at 138C./1.35 mm. of mercury. The purebis(N-pyrrolidinyl)methylene-1,3-dimethyl-Z-imidazolidine was alsocharacterized by its IR and n-m-r spectra.

AnaIysfs.Calcd. for C H N (percent): C, 67.2; H, 10.5; N, 22.4. Found(percent): C, 66.8; H, 10.7; N, 22.3.

Part B.Aerosol By the procedure of Example 1, an aerosol was preparedfrom 11.5 parts of bis(N-pyrrolidinyl)methylene-1,3-dimethyl-2imidazolidine, 11.5 parts of decane containing 4% decylalcohol by weight and 23 parts of a 30/70 mixture ofdichlorodifluoromethane/trichlorofluoromethane by weight. Materialdeposited from the aerosol on a surface contacting air chemiluminescedwith short duration.

Since obvious modifications and equivalents in the application will beevident to those skilled in the chemical arts, I propose to be boundsolely by the appended claims.

I claim:

1. An aerosol composition consisting essentially of a mixture of:

(1) an effective chemiluminescent amount of at least onechemiluminescent tetrakis(disubstitutedamino) ethylene of the formulawherein the Rs may be alike or different and are selected from the groupconsisting of monovalent alkyl and cycloalkyl of up to 10 carbons; inthe case of two Rs joined to the same N, divalent alkylene forming withthe N a 3- to S-membered monoaza heterocycle; and, in the case of two Rsjoined to different Ns, divalent alkylene forming with the two Ns a 4-to 7-membered diaza heterocycle; and

(2) at least one compatible inert nonquenching aerosol propellant;

said composition being maintained under pressure in a container.

2. A composition of claim 1 containing, as a chemiluminescent material,tetrakis(dimethylamino)ethylene.

3. A composition of claim 1 containing, as a chemiluminescent material,l,1',3,3'-tetramethyl-A '-bi(imidazolidine).

4. A composition of claim 1 containing, as a chemiluminescent material,1,1,3,3'-tetraethyl-A '-bi(imidazolidine).

5. A composition of claim 1 containing, as a chemiluminescent material,1,1,3,3'-tetra-n-butyl-A -bi(imidazolidine).

6. A composition of claim 1 containing, as a chemiluminescent material,tetrakis(N-pyrrolidinyl)ethylene.

7. A composition of claim 1 containing, as a chemiluminescent material,1,1,2-tris(N-pyrrolidinyl) dimethylaminoethylene.

8. A composition of claim 1 containing, as a chemiluminescent material,bis(N-pyrrolidinyl)methylene-1,3- dimethyl-Z-imidazolidine.

A composition of claim 1 containing, additionally, s1 ica.

10. A composition of claim 1 containing, as an aerosol propellant, afluorinated hydrocarbon.

References Cited UNITED STATES PATENTS 3,264,221 8/1966 Winberg 252188.3

LEON D. ROSDOL, Primary Examiner J. D. WELSH, Assistant Examiner US. Cl.X.R.

